YARA · Signature Base (Florian Roth / Nextron)
SIGNATURE_BASE_MAL_Icedid_GZIP_LDR_202104
2021 initial Bokbot / Icedid loader for fake GZIP payloads
- Author
- Thomas Barabosch, Telekom Security
- Date
- 2021-04-12
- Modified
- 2023-01-27
- Score / Quality
- 75 / 85
What this rule detects
2021 initial Bokbot / Icedid loader for fake GZIP payloads
Associated malware family: Icedid.
Targets: Windows PE.
It defines 11 patterns (11 text, 0 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
rule SIGNATURE_BASE_MAL_Icedid_GZIP_LDR_202104 : FILE
{
meta:
= "2021 initial Bokbot / Icedid loader for fake GZIP payloads"
= "Thomas Barabosch, Telekom Security"
= "fbf578e7-c318-5f67-82df-f93232362a23"
= "2021-04-12"
= "2023-01-27"
= "https://www.telekom.com/en/blog/group/article/let-s-set-ice-on-fire-hunting-and-detecting-icedid-infections-627240"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/crime_icedid.yar#L14-L40"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
= "7a7cc6c7dcbf43bace6a1f259af38560327c34386517e719ad81068b2d9b6659"
= 75
= 85
= "FILE"
strings:
$internal_name = "loader_dll_64.dll" fullword
$string0 = "_gat=" wide
$string1 = "_ga=" wide
$string2 = "_gid=" wide
$string4 = "_io=" wide
$string5 = "GetAdaptersInfo" fullword
$string6 = "WINHTTP.dll" fullword
$string7 = "DllRegisterServer" fullword
$string8 = "PluginInit" fullword
$string9 = "POST" wide fullword
$string10 = "aws.amazon.com" wide fullword
condition:
uint16( 0 ) == 0x5a4d and filesize < 5000KB and ( $internal_name or all of ( $s* ) ) or all of them
}
Strings (11 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $internal_name | text | "loader_dll_64.dll" | fullword |
| $string0 | text | "_gat=" | wide |
| $string1 | text | "_ga=" | wide |
| $string2 | text | "_gid=" | wide |
| $string4 | text | "_io=" | wide |
| $string5 | text | "GetAdaptersInfo" | fullword |
| $string6 | text | "WINHTTP.dll" | fullword |
| $string7 | text | "DllRegisterServer" | fullword |
| $string8 | text | "PluginInit" | fullword |
| $string9 | text | "POST" | wide fullword |
| $string10 | text | "aws.amazon.com" | wide fullword |
Condition
uint16( 0 ) == 0x5a4d and filesize < 5000KB and ( $internal_name or all of ( $s* ) ) or all of themIn plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- The file must be smaller than 5000KB (a cheap guard that skips large files).
- All patterns in ( $s* ) must match.
- All patterns in the rule must match.
- Pattern $internal_name must be present.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
Licence & attribution
Author: Thomas Barabosch, Telekom Security
Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a
Licence: Detection Rule License 1.1 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: fbf578e7-c318-5f67-82df-f93232362a23
Tags:FILE
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